Carotenoids are pigments produced by microorganisms, fungi and plants, and used by them as antioxidants and protectants against excessive radiation. The most widely used carotenoids in food, medical preparations or cosmetics are β-carotene and lycopene. β-Carotene and lycopene are sensitive to light and oxidation, a property which considerably limits their use and shortens shelf-life of products containing them (in: Carotenoids, Chemistry and Biology, Krinski, N. I., Matthews-Roth, M. M., Taylor, R. F., (Eds), Planum Press, New York, London, 1989). In addition, β-carotene and lycopene have a distinctive orange color and this color has a serious limitation for a variety of cosmetic or food applications.
Phytoene (7, 8, 11, 12, 7′, 8′, 11′, 12′-octahydro-γ,γ-carotene) and phytofluene (15Z, 7, 8, 11, 12, 7′, 8′-hexahydro-γ,γ-carotene), are carotenoids (C-40 isoprenoids chain) which are precursors in the biosynthetic pathway which leads to the production of β-carotene, lycopene and other carotenoids (phytoene is the first carotenoid-specific precursor and phytofluene is produced therefrom in a subsequent desaturation step). Phytoene is completely colorless whereas phytofluene has a slight yellowish color. Japanese Patent Application No. 90-40520, disclosed that the introduction of a DNA sequence yielding expression of phytoene into certain transfected cancer cells, resulted in inhibition of their growth and in inhibition in the activation of Epstein Barr virus (EBV).